[Form 4] Magnite, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Magnite director Paul Caine reported the sale of 5,000 shares of common stock on 08/11/2025. The sale was executed pursuant to a Rule 10b5-1 trading plan adopted on August 15, 2024, and the reported weighted average price was $22.29 (shares transacted at prices ranging from $22.07 to $22.67). After the reported transaction, the reporting person beneficially owned 178,603 shares directly.

The Form 4 shows the disposition was coded as a sale and filed by one reporting person who is identified as a director. The filer offered to provide transaction-level price details on request as noted in the explanatory footnote.

Positive

• Sale executed under a Rule 10b5-1 plan, indicating a pre-arranged trading schedule and procedural compliance
• Detailed price disclosure provided: weighted average price of $22.29 and range $22.07–$22.67, with an offer to provide per-price breakdowns on request
• Reporting person retains significant direct ownership after the sale: 178,603 shares

Negative

• Reduction in direct holdings of 5,000 shares (disposition reported)
• Potential perceived selling pressure from insider disposition, though magnitude is modest

Insights

Financial Analyst

TL;DR: Director sold a small portion of his stake under a pre-existing 10b5-1 plan; transaction appears procedural rather than a material shift.

The report discloses a disposition of 5,000 shares at a weighted average price of $22.29, executed under a Rule 10b5-1 plan adopted on August 15, 2024. The director retains 178,603 shares directly after the sale. Relative to the pre-sale position (implied 183,603 shares), the sale represents roughly 2.7% of the prior holding, indicating a modest liquidity event rather than a material reduction in insider ownership. From an investor perspective this is a routine, pre-arranged disposal with limited apparent impact on corporate fundamentals.

Corporate Governance Expert

TL;DR: Use of a documented 10b5-1 plan and explanatory footnote supports procedural transparency around the insider sale.

The filing identifies the transaction as covered by a Rule 10b5-1 plan, which provides an affirmative defense against insider trading claims when properly adopted. The explanatory note offers a weighted average price and a disclosed price range and commits to provide detailed per-price breakdowns on request, which enhances disclosure quality. The reporting person is listed as a director and the form was filed by a single reporting person, with ownership reported as direct.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

X

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Caine Paul

(Last) (First) (Middle)

C/O MAGNITE, INC.

1250 BROADWAY, 15TH FLOOR

(Street)

NEW YORK NY 10001

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
MAGNITE, INC. [ MGNI ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
08/11/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	08/11/2025		S(1)		5,000	D	$22.29(2)	178,603	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. This sale was made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 15, 2024.

2. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $22.07 to $22.67, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

	/s/ Aaron Saltz, attorney-in-fact	08/13/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What did Magnite (MGNI) director Paul Caine sell?

The filing reports a sale of 5,000 shares of Magnite common stock on 08/11/2025.

At what price were the MGNI shares sold?

The reported weighted average price was $22.29; the filing states transaction prices ranged from $22.07 to $22.67.

Was the sale part of a trading plan?

Yes. The sale was made under a Rule 10b5-1 trading plan adopted on August 15, 2024.

How many MGNI shares does the reporting person own after the sale?

After the reported transaction, the reporting person beneficially owned 178,603 shares (direct ownership).

What relationship does the reporting person have to Magnite?

The form identifies the reporting person, Paul Caine, as a Director of Magnite, Inc.